The effects of OxiDate 2.0, sodium hypochlorite, thyme oil, rosemary stem infusion and ginkgo leaf infusion were tested in vitro on the bacterial cells of Xanthomonas euvesicatoria, Clavibacter michiganensis subsp. michiganensis, and Pseudomonas syringae pv. tomato. All treatments significantly reduced bacterial populations except for the infusions. Tomato seed artificially inoculated with X. euvesicatoria was treated with OxiDate 2.0, NaOCl, thyme oil or hot water and assayed by dilution plating of seed washes. All treatments gave significant reductions. Germination was not affected. Seedlings grown for 14 days from treated seed were assayed for bacterial populations using dilution plating and real-time PCR. Bacterial transmission to seedlings occurred in all treatments although seedlings from treated seeds had significantly lower populations than the control. NaOCl and hot water were the most effective seed treatments for reducing pathogen populations.